Monday, January 10, 2005

LIGHT POLLUTION IN DISCOVERY PARK

I doubt if you've ever noticed, but take the time sometime to walk Discovery Park after dark. You'll learn one thing. Discovery Park has a light problem. Too much of it. Everywhere. Just try to take a long exposure photograph in the Park after dark, like I recently did.

It's got me to thinking about what this Park stands for and what we want it to look like. If the primary purpose of the Park is to create a refuge from the City, where the enjoyment of nature is more important than that of manmade things, where habitat takes precedence over structures, what is the sense of lighting the whole place up like any other residential street in the city? Of course, I doubt this is the result of anyones specific planning. Rather, it's the heritage of Fort Lawton community that was once here. With thousands of military personel working and living on the base, the natural tendency was to light the place up like there was no tomorrow. As the military purpose has faded, so have the buildings and roads. But I believe we've forgotten one important manmade effect - artificial lights.

There's another consideration. Cost. By my count there are at least 20 sodium vapor streetlights in the Park that are not needed. A conservative estimate of the energy consumption of each of these lights is approximately $100/year. That's $2000 per year, at a minimum, to light areas in the Park that are not needed for public safety and clearly negatively impact the wildlife potential of the Park.

The ill-effect of night time, artificial light on wild animals and their habitat is well docmented. Many nocturnal animals and plants depend on a fixed intensity and amount of darkness to complete their life cycles. The presence of continual nighttime utility lighting disrupts these natural rhythms. And unless you're in the Park after dark (against the rules) you won't be aware of the problem. By day large areas of the Park seem natural and relatively wild. Nightime is another story.

There have been lots of documented research on the ill effects of light pollution. Several of the sites are listed at the end of this essay. They're worth reading.

I know the biggest concern is safety and security. And those are entirely legitimate. Important intersections need to be lit, and parking lots must be illuminated. But if you have a chance to drive through the Park at night, take note of the number of unshielded streetlights that are on, at locations that really don't need them. Also, consider the amount of electricity that is being consumed to light these areas. My proposal would be to agree to turn off the more obviously redundant lights for a trial period - say 6 - 12 months, and track the number of crimes or accidents that occur during that time. My guess is that no-one would notice the difference - and the Park, along with the plants and animals that call it home, would be the better for it.


Websites to learn more about light pollution:

http://www.amtsgym-sdbg.dk/as/sky.htm
http://www.aas.org/~light/pollution.html
http://www.monmouth.com/~ksears/litepol1.htm
http://cfa-www.harvard.edu/cfa/ps/nelpag.html
http://www.darksky.org/

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